1. Field of the Invention
The present invention relates to a method of treating an individual during nicotine withdrawal. In particular, the present invention relates to treating an individual who is addicted to nicotine with Passiflora incarnata, or an extract thereof, to prevent withdrawal and craving symptoms during nicotine cessation to aid in smoking cessation.
2. Description of Related Art
Tobacco is the single greatest cause of disease and premature death today in America and is responsible for more than 440,000 deaths each year. Despite the morbidity, mortality, and cost to smoking, nearly 21% of all adult Americans continue to smoke.
Nicotine, the active ingredient responsible for the addictive nature of cigarette smoking and use of other nicotine containing products such as snuff, chew tobacco, and the like, exerts excitatory and inhibitory pharmacologic effects which account for its stimulating yet calming effects. The compound binds to central nicotinic receptors causing release of the neurotransmitter dopamine in the mesolimbic area, the corpus striatum, and the frontal cortex. An increase in dopamine levels in the nucleus accumbens has been shown related to the addictive properties of nicotine.
Dopaminergic projection to the nucleus accumbens arises from neurons in the central tegmental area (VTA). Dopamine release from VTA projections is related to both excitatory and inhibitory inputs. In rat studies, it has been demonstrated that the inhibitory input to the VTA neurons are primarily GABAergic. Therefore, GABA agonists which have an action to inhibit neuronal outflow via this pathway may theoretically modulate dopamine release.
Nicotine replacement therapy (NRT), bupropion and varenicline are currently FDA approved as smoking cessation aids in the United States.
Extracts of passion flower have been used in traditional and herbal medicines for anxiety, insomnia, and seizures, but controlled clinical studies of passion flower extract for these indications are limited. Passion flower extract has been examined in double blind studies and shown to treat generalized anxiety disorder similar to oxazepram, to help patients through opiate withdrawal, and to help alleviate presurgical anxiety. In laboratory rodents, passion flower extract or single chemical constituents of passion flower have been shown to be sedative, anxiolytic and anticonvulsant. Moreover, numerous studies in laboratory rodents have demonstrated that whole extracts or a specific benzoflavone moiety from passion flower are anxiolytic, antitussive and aphrodisiac and may reduce certain kinds of drug dependence other than nicotine. They have shown that the benzoflavone drug, given together with the addictive agent during the induction of dependence, reduced the symptoms of antagonist-precipitated withdrawal to morphine, alcohol, nicotine, diazepam and Δ9-tetrahydrocannabinol.
As demonstrated in previous studies, an acute injection of nicotine to rats results in increased locomotion, and daily injections result in sensitization to this effect. This hyperlocomotion effect is used as a model of nicotine addiction or withdrawal and agents that block the expression of this hyperlocomotion are considered useful in treating the signs of withdrawal from nicotine in humans.